High statistics measurement of the cross sections of gamma gamma --> pi+ pi- production.

The Belle collaboration Mori, T. ; Uehara, S. ; Watanabe, Y. ; et al.
J.Phys.Soc.Jap. 76 (2007) 074102, 2007.
Inspire Record 749358 DOI 10.17182/hepdata.51842

We report on a high statistics measurement of the total and differential cross sections of the process gamma gamma -> pi^+ pi^- in the pi^+ pi^- invariant mass range 0.8 GeV/c^2 < W < 1.5 GeV/c^2 with 85.9 fb^{-1} of data collected at sqrt{s}=10.58 GeV and 10.52 GeV with the Belle detector. A clear signal of the f_0(980) resonance is observed in addition to the f_2(1270) resonance. An improved 90% confidence level upper limit Br.(eta'(958) -> pi^+ pi^-) < 2.9 x 10^{-3} is obtained for P- and CP-violating decay of the eta'(958) meson using the most conservative assumption about the interference with the background.

1 data table match query

Total cross section.


High-statistics measurement of neutral pion-pair production in two-photon collisions

The Belle collaboration Uehara, S. ; Watanabe, Y. ; Adachi, I. ; et al.
Phys.Rev.D 78 (2008) 052004, 2008.
Inspire Record 786406 DOI 10.17182/hepdata.50151

We report a high-statistics measurement of differential cross sections for the process gamma gamma -> pi^0 pi^0 in the kinematic range 0.6 GeV <= W <= 4.0 GeV and |cos theta*| <= 0.8, where W and theta* are the energy and pion scattering angle, respectively, in the gamma gamma center-of-mass system. Differential cross sections are fitted to obtain information on S, D_0, D_2, G_0 and G_2 waves. The G waves are important above W ~= 1.6 GeV. For W <= 1.6 GeV the D_2 wave is dominated by the f_2(1270) resonance while the S wave requires at least one additional resonance besides the f_0(980), which may be the f_0(1370) or f_0(1500). The differential cross sections are fitted with a simple parameterization to determine the parameters (the mass, total width and Gamma_{gamma gamma}B(f_0 -> pi^0 pi^0)) of this scalar meson as well as the f_0(980). The helicity 0 fraction of the f_2(1270) meson, taking into account interference for the first time, is also obtained.

2 data tables match query

Differential cross section for W = 1.33, 1.35 and 1.37 GeV.

Total cross section for the cos(theta*) ranges 0.0 to 0.6 and 0.0 to 0.8.


Differential Cross-Sections for the pi0 Photoproduction at Theta (CM) = 90-Degrees and K (Lab) = 380-MeV-820-MeV

Jung, M. ; Kattein, J. ; Leu, P. ; et al.
BONN-HE-76-15, 1976.
Inspire Record 111677 DOI 10.17182/hepdata.50235

None

1 data table match query

No description provided.


Forward Photoproduction of Neutral Pions on Polarized Protons in the Third Resonance Region

Herr, H. ; Husmann, D. ; Jansen, W. ; et al.
Nucl.Phys.B 125 (1977) 157-161, 1977.
Inspire Record 118996 DOI 10.17182/hepdata.50398

Angular distributions of the target symmetry for the reaction γ + p → π 0 + p have been measured at the Bonn 2.5 GeV Electron Synchrotron at pion c.m. angles between 13° and 63° and photon energies of 1.0 and 1.1 GeV. The π 0 mesons were detected by their two decay photons with total absorption lead-glass Čerenkov counters. Butanol was used as target material in a continuous flow 3 He cryostat operating at 0.5 K and 25 kG. The π 0 counting rate from free protons in the butanol target was derived from the measurements of the differential cross section on hydrogen. The data are compared with data of other laboratories and the results of two recent partial-wave analyses.

1 data table match query

No description provided.


NEUTRAL PION PHOTOPRODUCTION ON THE DEUTERON

Imanishi, A. ; Ishii, T. ; Kato, S. ; et al.
Phys.Rev.Lett. 54 (1985) 2497-2500, 1985.
Inspire Record 220232 DOI 10.17182/hepdata.20385

Large-angle cross sections for γd→π0d are systematically measured in the photon energy range between 500 and 1000 MeV. A good fit is obtained by use of a Glauber-model calculation which includes the dibaryon resonances F33(2.26) and G41(2.51), but the fit has an unusual nature in the role of resonance and nonresonance contributions.

1 data table match query

Liquid hydrogen target for final calibration.


Total hadronic cross-section of gamma rays in hydrogen in the energy range 0.265-GeV to 4.215-GeV

Armstrong, T.A. ; Hogg, W.R. ; Lewis, G.M. ; et al.
Phys.Rev.D 5 (1972) 1640-1652, 1972.
Inspire Record 67298 DOI 10.17182/hepdata.22462

The total cross section of γ rays in hydrogen resulting in hadron production, σT, has been measured over the energy range 265-4215 MeV. A tagging system with narrow energy bins was employed. Structure in the resonance region followed by a steady fall with energy has been observed and the results are analyzed. The forward amplitude of γ-proton scattering is evaluated, and its behavior in the Argand diagram studied as a function of energy. The relationships of the measurements to Regge-pole theory and the vector-dominance model are detailed.

2 data tables match query

No description provided.

SPIN AVERAGED FORWARD COMPTON SCATTERING AMPLITUDE. IM(AMP) WAS CALCULATED VIA THE OPTICAL THEOREM FROM A SMOOTH FIT TO THE DATA, AND USED IN THE DISPERSION RELATION TO CALCULATE RE(AMP). AT THRESHOLD THE THOMSON AMPLITUDE IS -3.0 MUB*GEV.


Charged-pi photoproduction at 180 degress in the energy range between 300 and 1200 mev

Fujii, T. ; Okuno, H. ; Orito, S. ; et al.
Phys.Rev.Lett. 26 (1971) 1672-1675, 1971.
Inspire Record 68981 DOI 10.17182/hepdata.21616

The differential cross sections at 180° for the reactions γ+p→π++n and γ+n→π−+p were measured using a magnetic spectrometer to detect π± mesons. In order to reduce the spread of energy resolution due to the nucleon motion inside the deuteron, a photon difference method was employed with a 50-MeV step for the reaction γ+n→π−+p. The data show structures at the second- and the third-resonance regions for both reactions. A simple phenomenological analysis was made for fitting the data, and the results are compared with those of previous analyses.

2 data tables match query

No description provided.

No description provided.


Proton Compton Scattering Measurement From 450 to 1350 MeV Near 90-degrees in the Center-of-Mass System

Rust, D.R. ; Eisenhandler, E. ; Mostek, P.J. ; et al.
Phys.Rev.Lett. 15 (1965) 938-941, 1965.
Inspire Record 944922 DOI 10.17182/hepdata.21794

None

1 data table match query

No description provided.


Proton form factors from elastic electron-proton scattering

Janssens, T. ; Hofstadter, R. ; Hughes, E.B. ; et al.
Phys.Rev. 142 (1966) 922-931, 1966.
Inspire Record 49127 DOI 10.17182/hepdata.26698

Absolute measurements of the elastic electron-proton cross section have been made with a precision of about 4% for values of the square of the four-momentum transfer, q2, in the range 6.0 to 30.0 F−2 and for electron scattering angles in the range 45° to 145°. To within the experimental errors, it is found that the charge and magnetic form factors of the proton have a common dependence on q2 when normalized to unity at q2=0, and that an accurate representation of the behavior of the form factor and that of the cross sections themselves can be given in terms of a three-pole approximation to the dispersion theory of nucleon form factors.

10 data tables match query

Axis error includes +- 2./2. contribution (RANDOM ERROR).

Axis error includes +- 2./2. contribution (RANDOM ERROR).

Axis error includes +- 2./2. contribution (RANDOM ERROR).

More…

pi+ Photoproduction from Hydrogen at Lab Angles from 34-degrees to 155-degrees and Lab Photon Energies from 500 to 1350 MeV

Thiessen, Henry A. ;
Phys.Rev. 155 (1967) 1488-1496, 1967.
Inspire Record 52277 DOI 10.17182/hepdata.26588

The differential cross section for the reaction γ+p→π++n was measured using the Caltech 1.5-GeV electron synchrotron. The positive pions were detected and momentum analyzed in a multichannel magnetic spectrometer and the data were recorded in the memory of a pulse-height analyzer. The energy resolution was improved over previous experiments and an attempt was made to minimize systematic errors. The data are presented in the form of energy distributions at 12 lab angles from 34° to 155°, and the range of lab proton energies extended from 500 to 1350 MeV. Data were not taken at all energies for each angle, since the maximum useful momentum of the spectrometer, 600 MeVc, restricted the maximum energy for lab angles less than or equal to 74°.

1 data table match query

No description provided.


Positive-Pion Production Asymmetry with Polarized Bremsstrahlung Near Second Resonance

Liu, F.F. ; Vitale, S. ;
Phys.Rev. 144 (1966) 1093-1100, 1966.
Inspire Record 50917 DOI 10.17182/hepdata.26643

The azimuthal asymmetry Σ=(σ⊥−σII)(σ⊥+σII) in π+ photoproduction by linearly polarized bremsstrahlung was measured at photon energies from 475 to 750 MeV at 90° and 135° in the center-of-mass system. The experimental results show that even in this energy region, π+ are produced predominantly in the plane of the magnetic vector.

1 data table match query

No description provided.


Photoproduction of pi0 Mesons from Hydrogen near Zero Degrees

Highland, V.L. ; DeWire, J.W. ;
Phys.Rev. 132 (1963) 1293-1297, 1963.
Inspire Record 944974 DOI 10.17182/hepdata.26730

We report measurements of the differential cross section for photoproduction of π0 mesons from hydrogen, with the pion emerging near 0 deg, in the photon energy range 290 to 700 MeV. The results show no unusual behavior of the cross section in the forward direction. They are consistent with the angular distribution characteristic of a magnetic-dipole transition to a P32 state. The results agree reasonably well with theoretical predictions of Gourdin and Salin, but disagree with a prediction of DeTollis and Verganelakis. Least-squares fits in powers of cosθ have been made to the available angular distributions.

1 data table match query

No description provided.


Polarization of the Recoil Proton from pi0 Photoproduction in Hydrogen

Maloy, J.O. ; Peterson, V.Z. ; Salandin, G.A. ; et al.
Phys.Rev. 139 (1965) B733-B746, 1965.
Inspire Record 944960 DOI 10.17182/hepdata.26657

The polarization of the recoil proton in neutral single-pion photoproduction from hydrogen, γ+p→p+π0, has been measured for pion center-of-mass angles near 90° at 7 photon energies from 450 to 900 MeV. The polarization rises to a maximum of 0.58 near 600 MeV and is still 0.42 at 900 MeV. The sign of the polarization is negative in the sense of k×q, where k is the photon momentum and q is the pion momentum. The measured values are given as functions of laboratory photon energy and c.m. pion angle as follows: 450 MeV, 109°, -0.16±0.14; 525 MeV, 84°, -0.36±0.19; 585 MeV, 86°, -0.58±0.15; 660 MeV, 77°, -0.51±0.17; 755 MeV, 76°, -0.55±0.15; 810 MeV, 89°, -0.45±0.17; 895 MeV, 90°, -0.42±0.16. The recoil protons were momentum-analyzed with a magnetic spectrometer. Nuclear emulsion was used as scatterer and detector. The emulsion technique is discussed in detail. The number of individual scatterings in emulsion used for each measurement varied between 750 and 1000.

1 data table match query

No description provided.


Pion Pair Production From $\gamma \gamma$ Interactions at {PEP} and the Radiative Width of the F0 Meson

The DELCO collaboration Courau, A. ; Johnson, R.P. ; Sherman, S.S. ; et al.
Phys.Lett.B 147 (1984) 227-231, 1984.
Inspire Record 202552 DOI 10.17182/hepdata.30498

Results are presented of an untagged e + e − → e + e − + π + π − experiment performed at PEP with the DELCO detector. In the invariant-mass range 0.7 ⩽ W ππ < 2.0 GeV/ c 2 , the QED e + e − background is identified and eliminated, and both the π + π − predictions and the μ + μ − and K + K − background substractions are normalized to the measurement of the e e + e − events. The results agree with a simple model of superposition and interference of the f 0 (1270) resonance, produced with helicity 2, with a Born-term continuum. From a fit of the model to the data, the radiative width of the f 0 is determined to be Γ f 0 → γγ = 2.70 ± 0.21 keV.

1 data table match query

Data read from graph.


Differential Cross-Sections of the Proton Compton Scattering in the Energy Between 450-MeV and 950-MeV

Toshioka, K. ; Chiba, M. ; Kato, S. ; et al.
Nucl.Phys.B 141 (1978) 364-378, 1978.
Inspire Record 120614 DOI 10.17182/hepdata.34955

The differential cross sections of the proton Compton scattering around the second resonance have been measured at a c.m. angle of 90° for incident photon energies between 450 MeV and 950 MeV in steps of 50 MeV, and at an angle of 60° for energies between 600 MeV and 800 MeV. The results show that the peak of the 2nd resonance agrees with that of the pion photoproduction process. We also calculated the proton Compton scattering based on unitarity and fixed- t dispersion relations. The calculation describes well the data of the cross section and the recoil proton polarization.

1 data table match query

No description provided.


The Measurement of Polarized Target Asymmetry on gamma p --> pi0 p Below 1-GeV

Fukushima, M. ; Horikawa, N. ; Kajikawa, R. ; et al.
Nucl.Phys.B 136 (1978) 189-200, 1978.
Inspire Record 119548 DOI 10.17182/hepdata.35100

The polarized target asymmetry in the reaction γ p → π 0 p has been measured at c.m. angles of 30°, 80°, 105° and 120° for incident photon energies below 1 GeV. Two decay photons from π 0 were detected in coincidence at 30°, and at the other angles recoil protons and single photons from π 0 were detected. The results are compared with recent phenomenological analyses.

1 data table match query

No description provided.


The Measurement of Polarized Target Asymmetry on gamma p --> pi+ n Below 1.02-GeV

Fukushima, M. ; Horikawa, N. ; Kajikawa, R. ; et al.
Nucl.Phys.B 130 (1977) 486-504, 1977.
Inspire Record 119547 DOI 10.17182/hepdata.35243

The polarized target asymmetry for the process γ p → π + n has been measured for incident photon energies below 1.02 GeV over a range of c.m. angles from 40° to 160°. π + mesons from a polarized butanol target were detected by a magnetic spectrometer. The results are compared with predictions given by existing analyses. A tentative interpretation of the data is performed, and a larger contribution of S-wave resonances is suggested. The photocouplings of dominant resonances were hardly changed by the inclusion of new data and they seem to be almost uniquely determined.

1 data table match query

No description provided.


Polarized Target Asymmetry in pi0 Photoproduction Between 0.4-GeV and 1.0-GeV Around 100-Degrees

Feller, P. ; Fukushima, M. ; Horikawa, N. ; et al.
Phys.Lett.B 55 (1975) 241-244, 1975.
Inspire Record 90929 DOI 10.17182/hepdata.35716

The polarized target asymmetry in the reaction γp→π°p has been measured at c.m. angles around 100° for photon energies between 0.4 and 1.0 GeV by detecting both the recoil proton and the π°. The result is compared with recent analyses.

1 data table match query

No description provided.


Rho Production by Virtual Photons

Joos, P. ; Ladage, A. ; Meyer, H. ; et al.
Nucl.Phys.B 113 (1976) 53-92, 1976.
Inspire Record 108749 DOI 10.17182/hepdata.35708

The reaction γ V p → p π + π − was studied in the W , Q 2 region 1.3–2.8 GeV, 0.3–1.4 GeV 2 using the streamer chamber at DESY. A detailed analysis of rho production via γ V p→ ϱ 0 p is presented. Near threshold rho production has peripheral and non-peripheral contributions of comparable magnitude. At higher energies ( W > 2 GeV) the peripheral component is dominant. The Q 2 dependence of σ ( γ V p→ ϱ 0 p) follows that of the rho propagator as predicted by VDM. The slope of d σ /d t at 〈 Q 2 〉 = 0.4 and 0.8 GeV 2 is within errors equal to its value at Q 2 = 0. The overall shape of the ϱ 0 is t dependent as in photoproduction, but is independent of Q 2 . The decay angular distribution shows that longitudinal rhos dominate in the threshold region. At higher energies transverse rhos are dominant. Rho production by transverse photons proceeds almost exclusively by natural parity exchange, σ T N ⩾ (0.83 ± 0.06) σ T for 2.2 < W < 2.8 GeV. The s -channel helicity-flip amplitudes are small compared to non-flip amplitudes. The ratio R = σ L / σ T was determined assuming s -channel helicity conservation. We find R = ξ 2 Q 2 / M ϱ 2 with ξ 2 ≈ 0.4 for 〈 W 〉 = 2.45 GeV. Interference between rho production amplitudes from longitudinal and transverse photons is observed. With increasing energy the phase between the two amplitudes decreases. The observed features of rho electroproduction are consistent with a dominantly diffractive production mechanism for W > 2 GeV.

1 data table match query

DIPION CHANNEL CROSS SECTION.


Polarized Target Asymmetry in $\pi^+$ Photoproduction Between 0.3-GeV and 1.0-GeV at 130°

Feller, P. ; Fukushima, M. ; Horikawa, N. ; et al.
Nucl.Phys.B 102 (1976) 207, 1976.
Inspire Record 90055 DOI 10.17182/hepdata.36079

The polarized target asymmetry for γ + p → π + + n was measured at c.m. angles around 130° for the energy range between 0.3 and 1.0 GeV. A magnetic spectrometer system was used to detect π + mesons from the polarized butanol target. The data show two prominent positive peaks at 0.4 and 0.8 GeV and a deep minimum at 0.6 GeV. These features are well reproduced by the phenomenological analysis made by us.

1 data table match query

No description provided.


Compton scattering by the proton through Theta(CMS) = 75-degrees and 90-degrees in the Delta resonance region

Hünger, A ; Peise, J ; Robbiano, A ; et al.
Nucl.Phys.A 620 (1997) 385-416, 1997.
Inspire Record 458618 DOI 10.17182/hepdata.36349

Differential cross sections for Compton scattering by the proton have been measured in the energy interval between 200 and 500 MeV at scattering angles of θ cms = 75° and θ cms = 90° using the CATS, the CATS/TRAJAN, and the COPP setups with the Glasgow Tagger at MAMI (Mainz). The data are compared with predictions from dispersion theory using photo-meson amplitudes from the recent VPI solution SM95. The experiment and the theoretical procedure are described in detail. It is found that the experiment and predictions are in agreement as far as the energy dependence of the differential cross sections in the Δ-range is concerned. However, there is evidence that a scaling down of the resonance part of the M 1+ 3 2 photo-meson amplitude by (2.8 ± 0.9)% is required in comparison with the VPI analysis. The deduced value of the M 1+ 3 2 - photoproduction amplitude at the resonance energy of 320 MeV is: |M 1+ 3 2 | = (39.6 ± 0.4) × 10 −3 m π + −1 .

1 data table match query

No description provided.


Polarisation of recoil neutrons from single-pion photoproduction off protons in the resonance region

Hahn, U. ; Wallraff, W. ; Weingarten, W. ;
BONN-PI-1-143, 1971.
Inspire Record 1498199 DOI 10.17182/hepdata.75407

None

1 data table match query

No description provided.


Measurement of the polarization of the backscattered neutron from the reaction gamma p -> pi n in the region of the second resonance

Wallraff, Wolfgang ;
BONN-PI-1-162, 1972.
Inspire Record 1498200 DOI 10.17182/hepdata.75411

None

1 data table match query

No description provided.


ASYMMETRY MEASUREMENTS IN PION PHOTOPRODUCTION BY POLARIZED PHOTONS IN THE ENERGY RANGE FROM 250-MeV TO 600-MeV

Antufev, Yu.P. ; Agranovich, V.L. ; Ganenko, V.B. ; et al.
PRINT-70-2307, 1970.
Inspire Record 1105361 DOI 10.17182/hepdata.75432

None

1 data table match query

No description provided.


PROTON COMPTON EFFECT

Nagashima, Yorikiyo ;
INSJ-81, 1964.
Inspire Record 1101996 DOI 10.17182/hepdata.69229

None

2 data tables match query

No description provided.

No description provided.


A STUDY OF DOUBLE TAGGED TWO PHOTON REACTIONS AT SPEAR

Biddick, C.J. ; Burnett, T.H. ; Lyon, D.E. ; et al.
Phys.Lett.B 97 (1980) 320, 1980.
Inspire Record 159793 DOI 10.17182/hepdata.27144

We have identified 262 doubly tagged two-photon events. A subset of the data shows an enhancement of 21 events in the inclusive two-photon mass squared distribution between 0.8 and 2.2 GeV 2 . If these events result from spin 2 resonance production then Γ γγ = 9.5 ± 3.9 ± 2.4 keV (statistical and systematic). From another subset of 58 events in which the final state could be classified we determine the two-photon hadron to muon cross section ratio R γγ = 1.1 ± 0.3 ± 0.3.

1 data table match query

ELECTRON BEAM ENERGIES OF 3.0 AND 3.6 GEV.


INELASTIC ELECTRON PHOTON SCATTERING AT MODERATE FOUR MOMENTUM TRANSFERS

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Phys.Lett.B 99 (1981) 287-291, 1981.
Inspire Record 155594 DOI 10.17182/hepdata.27125

We present new high statistics data on hadron production in photon-photon reactions. The data are analyzed in terms of an electron-photon scattering formalism. The dependence of the total cross section of Q 2 , the four-momentum transfer squared of the scattered electron, and on the mass W of the hadronic system is investigated. The data are compared to predictions from Vector-Meson Dominance and the quark model.

1 data table match query

DEPENDENCE ON VISIBLE HADRONIC INVARIANT MASS.


Forward Electroproduction of Single Charged Pions in the Resonance Region Using a Deuterium Target

Morris, J.V. ; Darvill, D.C. ; Davenport, M. ; et al.
Phys.Lett.B 73 (1978) 495-499, 1978.
Inspire Record 122614 DOI 10.17182/hepdata.27480

The rates for forward electroproduction of single charged pions from deutrium have been measured in the resonance region, at a virtual photon mass squared ≈−0.5( GeV/ c 2 ) 2 . Results are presented in the form of a π − to π + cross-section ratio.

1 data table match query

No description provided.


Photoproduction of Neutral Pions at Forward Angles

Berkelman, Karl ; Waggoner, James A. ;
Phys.Rev. 117 (1960) 1364-1375, 1960.
Inspire Record 46817 DOI 10.17182/hepdata.26899

The bremsstrahlung beam of the Cornell Bev electron synchrotron has been used to study the reaction γ+p→π0+p over the photon energy range 250 Mev to 1 Bev, and for center-of-mass pion angles between 20° and 70°. The recoil protons, of energies between 10 and 60 Mev, were identified and their energies determined using a range telescope of eight thin plastic scintillators enclosed in a vacuum chamber with the thin liquid hydrogen target. Correlated pulse-height information was obtained by photographing an oscilloscope display and was used to sort out the protons from mesons and electrons. Corrections were made for the background of photoprotons from the Mylar target cup, the energy loss of the protons in the liquid hydrogen, absorption and scattering in the counter telescope, and the variation of beam intensity profile with energy. Compared with previous experiments and extrapolations the results show a somewhat smaller forward differential cross section above 400 Mev. The angular distributions obtained from a least-squares fit to all existing data indicate a d32 assignment for the 760-Mev resonance level. Other implications of the data are also discussed.

1 data table match query

No description provided.


High-Energy Photoproduction of pi0 Mesons from Hydrogen

DeWire, J.W. ; Jackson, H.E. ; Littauer, Raphael ;
Phys.Rev. 110 (1958) 1208-1209, 1958.
Inspire Record 944997 DOI 10.17182/hepdata.26907

None

1 data table match query

No description provided.


Photoproduction of Neutral Pions at Energies 500 to 940 Mev

Vette, J.I. ;
Phys.Rev. 111 (1958) 622-631, 1958.
Inspire Record 944995 DOI 10.17182/hepdata.26859

The process γ+p→π0+p has been studied by detecting recoil protons from a liquid hydrogen target which was bombarded by the bremsstrahlung beam of the California Institute of Technology electron synchrotron. The angle and momentum of the recoil protons were measured by a magnetic spectrometer-three scintillation counter coincidence system. The process has been studied between photon laboratory energies of 490 and 940 Mev and between pion center-of-mass angles of 31.5° and 147°. Protons which arose from meson pair production were significant at forward laboratory angles. A correction for this contamination is discussed. The results of these measurements show two interesting features. One is that the total cross section, which falls very rapidly above the 32−32 resonance energy near 320 Mev, reaches a minimum at about 600 Mev, and then increases to a broad maximum near 800 or 900 Mev. The other striking feature of the data is that the shape of the angular distribution seems to change rather suddenly near 900 Mev.

1 data table match query

No description provided.


Photoproduction of pi+ Mesons from Hydrogen in the Region 350-900 Mev

Heinberg, M. ; McClelland, W.M. ; Turkot, F. ; et al.
Phys.Rev. 110 (1958) 1211-1212, 1958.
Inspire Record 46812 DOI 10.17182/hepdata.26860

None

1 data table match query

No description provided.


FORWARD ELECTROPRODUCTION OF CHARGED PIONS FROM DEUTERONS AT Q**2 = 1.0-GeV/c**2

Morris, J.V. ; Darvill, D.C. ; Davenport, M. ; et al.
Phys.Lett.B 86 (1979) 211-214, 1979.
Inspire Record 140702 DOI 10.17182/hepdata.27310

The ratio of π - to π + electroproduction cross sections from deuterium has been measured in the resonance region, at a four-momentum transfer squared close to −1.0 (GeV/ c ) 2 . Results in the forward direction are presented and a comparison is made with predictions based on SU(6) W and the Melosh transformation.

1 data table match query

No description provided.


Hadron Production From Photon - Photon Interactions in the Center-of-mass Energy Range From 1-{GeV} to 5-{GeV}

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Phys.Lett.B 89 (1979) 120-124, 1979.
Inspire Record 142875 DOI 10.17182/hepdata.27291

We present the first data on photon-photon annihilation into hadrons for CM energies > 1 GeV obtained with the detector PLUTO at the e + e − storage ring PETRA. Cross sections are extracted using an inelastic eγ scattering formalism. The results are compared to expectations from Regge-like models.

1 data table match query

DEPENDENCE OF CROSS SECTION FOR ELECTRON-PHOTON SCATTERING (ANALOGOUS TO HAND'S FORMULA) ON VISIBLE HADRONIC ENERGY, CALCULATED BY TAKING PION MASSES FOR ALL CHARGED PARTICLES.


Some differential cross-section for neutral pion photoproduction in the photon energy range 350-850 mev

Dougan, P. ; Kivikas, T. ; Lugner, K. ; et al.
Phys.Lett.B 49 (1974) 194-196, 1974.
Inspire Record 95300 DOI 10.17182/hepdata.27968

The preliminary results of measurements of differential cross-sections for the photo-production of neutral pions from protons are given. The data fall in the range 60–125 degrees in pion c.m. angle and 350 to 850 MeV in photon energy.

5 data tables match query

Axis error includes +- 10/10 contribution (ESTIMATED ERROR DUE TO PRELIMINARY NATURE OF DATA).

Axis error includes +- 10/10 contribution (ESTIMATED ERROR DUE TO PRELIMINARY NATURE OF DATA).

Axis error includes +- 10/10 contribution (ESTIMATED ERROR DUE TO PRELIMINARY NATURE OF DATA).

More…

Inclusive hadron photoproduction from longitudinally polarized protons and deuterons.

The E155 collaboration Anthony, P.L. ; Arnold, R.G. ; Averett, T. ; et al.
Phys.Lett.B 458 (1999) 536-544, 1999.
Inspire Record 495554 DOI 10.17182/hepdata.28074

We report measurements of the asymmetry A_parallel for inclusive hadron production on longitudinally polarized proton and deuteron targets by circularly polarized photons. The photons were produced via internal and external bremsstrahlung from an electron beam of 48.35 GeV. Asymmetries for both positive and negative signed hadrons, and a subset of identified pions, were measured in the momentum range 10<P<30 GeV at 2.75 and 5.5 degrees. Small non-zero asymmetries are observed for the proton, while the deuteron results are consistent with zero. Recent calculations do not describe the data well.

2 data tables match query

The asymmetry for polarized photoproduction of inclusive hadrons from a polarized proton target. The errors are statistical only.

The asymmetry for polarized photoproduction of inclusive identified pions from a polarized proton target. The errors are statistical only.


Neutral pion photoproduction from protons at forward angles in the energy region between 350 mev and 1175 mev

Hemmi, Y. ; Inagaki, Y. ; Inagaki, T. ; et al.
Phys.Lett.B 43 (1973) 79-84, 1973.
Inspire Record 84945 DOI 10.17182/hepdata.28128

The differential cross section for the reaction γp → π 0 p at forward angles has been measured in the energy region between 350 MeV and 1175 MeV. A phenomenological multiple analysis was carried out on the present data together with other data.

1 data table match query

No description provided.


Coincidence electroproduction of single neutral pions in the resonance region at q 2 = 0.5 (GeV/ c ) 2

Latham, A. ; Allison, J. ; Booth, I. ; et al.
Nucl.Phys.B 156 (1979) 58-92, 1979.
Inspire Record 1392686 DOI 10.17182/hepdata.836

Data are presented for the reaction ep → ep π 0 at a nominal four-momentum transfer squared of 0.5 (GeV/ c ) 2 . The data were obtained using an extracted electron beam from NINA and two magnetic spectrometers for coincidence detection of the electron and proton. Details are given of the experimental method and the results are given for isobar masses in the range 1.19 – 1.73 GeV/ c 2 .

4 data tables match query

No description provided.

No description provided.

Backward cross sections.

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Tensor Meson Excitation in the Reaction $\gamma \gamma \to K^0_S K^0_S$

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Lackas, W. ; et al.
Z.Phys.C 37 (1988) 329, 1988.
Inspire Record 250982 DOI 10.17182/hepdata.15690

In the analysis of the reactione+e−→e+e−KS0Ks0 clear evidence for exclusive γγ→f2′ resonance production is observed. The productΓγγ ·B(f2′→K\(\bar K\)) is measured to be 0.10−0.03−0.02+0.04+0.03 keV independent of ana priori assumption on the helicity structure. Our data are consistent with a pure helicity 2 contribution and we derive an upper limit for the ratioΓγγ(0)/Γγγ. The absence of events in the mass region around 1.3 GeV clearly proves destructivef2−a2 interference and allows to measure the relative phases betweenf2,a2 andf2′. Upper limits on the production of the glueball candidate statesf2(1720) andX(2230) as well as theKS0KS0-continuum are given.

1 data table match query

Data read from graph.


Measurement of the Radiative Width of the A(2) (1320) in Two Photon Interactions

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Gerhards, R. ; et al.
Z.Phys.C 31 (1986) 537, 1986.
Inspire Record 228876 DOI 10.17182/hepdata.15859

The reactione+e−→e+e− A2 (1320) has been observed by detecting the decayA2→π+,π-π0. The two-photon width of theA2 has been measured to be Г(A2→γγ)=(0.09±0.27 (stat)±0.16 (syst)) keV. The cross section σ(γγ→π+,π-π0 has been determined outside theA2 resonance region.

1 data table match query

Data read off a graph.


Search for Two Photon Production of Resonances Decaying Into $K \bar{K}$ and $K \bar{K} \pi$

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Z.Phys.C 29 (1985) 189, 1985.
Inspire Record 220941 DOI 10.17182/hepdata.16018

An analysis of the production ofKS0KS0 andK±Ks0π∓ by two quasi-real photons is presented. The cross section forγγ→K0\(\overline {K^0 } \), which is given for the γγ invariant mass range fromK\(\bar K\) threshold to 2.5 GeV, is dominated by thef′(1525) resonance and an enhancement near theK\(\bar K\) threshold. Upper limits on the product of the two-photon width times the branching ratio intoK\(\bar K\) pairs are given forΘ(1700),h(2030), and ξ(2220). For exclusive two-photon production ofK±Ks0π∓ no significant signal was observed. Upper limits are given on the cross section ofγγ→K+\(\overline {K^0 } \)π− orK−K0π+ between 1.4 and 3.2 GeV and on the product of the γγ width times the branching ratio into theK\(\bar K\)π final states for theηc(2980) and the ι(1440), yieldingΓ(γγ)→i(1440))·BR(i(1440)→K\(\bar K\)π<2.2 keV at 95% C.L.

1 data table match query

Data read from graph.. Corrected for the angular distribution, which is assumed to be sin(theta)**4 for W > 1.14 GeV and isotropic in the first bin.


DIFFERENTIAL CROSS-SECTION FOR PI- P ---> GAMMA N FROM 427-MEV/C TO 625-MEV/C

Kim, G.J. ; Arends, J. ; Briscoe, W.J. ; et al.
Phys.Rev.D 40 (1989) 244-247, 1989.
Inspire Record 285141 DOI 10.17182/hepdata.23110

Differential cross sections for π−p→γn have been determined from 427 to 625 MeV/c, mainly at 90° and 110° c.m. The data were obtained by combining measurements of the Panofsky ratio in flight with known charge-exchange cross sections. The results are compared with γn→π−p data derived from γd experiments; the difference is typically 30%. The radiative decay amplitudes of neutral πN resonances are therefore uncertain by at least 30%.

3 data tables match query

Charge exchange cross section from PWA.

PI- P --> GAMMA N cross section.

GAMMA N --> PI- P cross section calculated using detailed balance.


Proton Polarization in gamma p --> pi0 p Reaction at an Angle of Theta (pi) = 100-Degrees in CMS in the Second pi n Resonance Region

Derebchinsky, A.I. ; Zybalov, A.A ; Konovalov, O.G. ; et al.
Yad.Fiz. 28 (1978) 265-266, 1978.
Inspire Record 135482 DOI 10.17182/hepdata.19013

None

1 data table match query

No description provided.


Pion and kaon pair production in photon-photon collisions

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.Lett. 57 (1986) 404, 1986.
Inspire Record 228072 DOI 10.17182/hepdata.20204

We report measurements of the two-photon processes e+e−→e+e−π+π− and e+e−→e+e−K+K−, at an e+e− center-of-mass energy of 29 GeV. In the π+π− data a high-statistics analysis of the f(1270) results in a γγ width Γ(γγ→f)=3.2±0.4 keV. The π+π− continuum below the f mass is well described by a QED Born approximation, whereas above the f mass it is consistent with a QCD-model calculation if a large contribution from the f is assumed. For the K+K− data we find agreement of the high-mass continuum with the QCD prediction; limits on f′(1520) and θ(1720) formation are presented.

2 data tables match query

Data read from graph. Additional overall systematic error 20% not included.

Data read from graph. Additional overall systematic error 20% not included.


Photoproduction of positive pions at 180 degrees from 0.22 to 3.1 gev

Bouquet, B. ; D' Almagne, B. ; Eschstruth, P.T. ; et al.
Phys.Rev.Lett. 27 (1971) 1244-1247, 1971.
Inspire Record 68896 DOI 10.17182/hepdata.21483

The π+ photoproduction cross section in hydrogen has been measured at 180° for photon energies from 0.22 to 3.1 GeV by detecting the pion in the backward direction. The statistical accuracy of the measurements varies typically from 3 to 10% depending on the energy. The data are compared with other recent experimental results and predictions of phenomenological theories.

1 data table match query

No description provided.


PHOTOPRODUCTION OF NEUTRAL PIONS ON HYDROGEN BELOW 500-MeV. 3. CROSS-SECTION MEASUREMENTS BETWEEN THE FIRST AND THE SECOND RESONANCE

Genzel, H. ;
Z.Phys. 268 (1974) 37-41, 1974.
Inspire Record 80489 DOI 10.17182/hepdata.2

Differential cross sections of neutral pion photoproduction on hydrogen were measured in the region between the first and the second nucleon resonance at photon energies of 400–500 MeV and were compared with results of an energy-independent multipole analysis.

1 data table match query

No description provided.


Angular distributions for single neutral pion photoproduction from neutrons at 450-800 mev

Bacci, C. ; Baldini-Celio, R. ; Esposito, B. ; et al.
Phys.Lett.B 39 (1972) 559-562, 1972.
Inspire Record 75766 DOI 10.17182/hepdata.28319

Differential cross sections for single photoproduction of neutral pion on neutron have been measured at different c.m. angles for photon energies, between 450–800 MeV.

1 data table match query

No description provided.


Total cross-section measurement for the three double pion production channels on the proton

Braghieri, A ; Murphy, L.Y ; Ahrens, J ; et al.
Phys.Lett.B 363 (1995) 46-50, 1995.
Inspire Record 382744 DOI 10.17182/hepdata.28464

The total cross sections for the three γp → Nππ reactions have been measured for photon energies from 400 to 800 MeV. The γ p → p π 0 π 0 and γ p → n π + π 0 cross sections have never been measured before while the γ p → p π + π − results are much improved compared to earlier data. These measurements were performed with the large acceptance hadronic detector DAPHNE, at the tagged photon beam facility of the MAMI microtron in Mainz.

3 data tables match query

No description provided.

No description provided.

No description provided.


Photoproduction of neutral pions from neutrons between 500 and 900 mev

Hemmi, Y. ; Inagaki, T. ; Kikuchi, R. ; et al.
Phys.Lett.B 32 (1970) 137-140, 1970.
Inspire Record 63812 DOI 10.17182/hepdata.28720

The differential cross sections for the γ + n → π O + n reaction have been measured at the photon energies of 500–900 MeV. The ratios, R oo = [ d δ d Ω(γ n → π o n ) ] [ d δ d Ω(γ p → π o p ) ] , have been obtained at the c.m. pion angles of 60 O , 90 O , 105 O , 120 O , and 140 O .

2 data tables match query

Axis error includes +- 0.0/0.0 contribution (8 TO 11////).

No description provided.


Measurement of asymmetry in spin dependent e p resonance region scattering.

Baum, Guenter ; Bergstrom, M.R. ; Clendenin, J.E. ; et al.
Phys.Rev.Lett. 45 (1980) 2000, 1980.
Inspire Record 154062 DOI 10.17182/hepdata.20698

The first measurements are reported of the asymmetry in resonance-region scattering of longitudinally polarized electrons by longitudinally polarized protons. Data have been obtained at Q2=0.5 and 1.5 (GeV/c)2 in the missing-mass range W=1.1−1.9 GeV. Results are compatible with a multipole analysis of single-pion electroproduction. The spin-dependent behavior is consistent with a duality mechanism as in the unpolarized case.

2 data tables match query

ELECTRON ASYMMETRY AT Q**2 ABOUT 0.5 GEV**2.

PHOTON ASYMMETRY AT Q**2 ABOUT 0.5 GEV**2.